Pulsating screen.



E. B. SYMONS. PULSIATING SCREEN. APPLICATlON FILED AUG.H. 1913. 1,151,976. Patented Aug. 31,1915.

2 SHEETSSHEET l.

E. B. SYMONS.

PULSATING SCREEN.

APPLICATION FILED Aue.11.1s1a.

Patented Aug. 31, 1915.

2 SHEETS-SHEET 2.

ME slams FATE EDGAR 2B. smonson CHICAGO, ILLINOIS.

. PULSATING SCREEN.

1,15LEW6.

Specification of Letters Patent.

Patented Aug. 31, 1915.

Application-filed August 11, 1913, Serial No. 784,064.

To all whom it may concern.-

Be it known that I, EDGAR B. SrMoNs, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Pulsating Screens, of

which the following is a specification.

My invention relates to improvements 1n screens, particularly those of the type known as pulsating screens. In such screen's where the screening fabric and the frame whlch carrles 1t is thrown up and down transversely there is a tendency for the screen to Figure 1 is a plan view with parts removed; Fig. 2 is a section along line 22 of s Fig. 1; and Fig. 3 is a sectionalong line 3-3 hopper.

A is a measuring gate pivoted on the hop-1 of Fig. 1.

. Like parts are indicated by the same letter throughout the several figures. A is a supporting frame or base open at top and bottom and adapted to be placed over the receptacle for the screened material which is not shown here. A is a hopper mounted thereupon.

A is" a feed chute discharging into th hopper.

' A is a feed per and free to swing back and forth beneath the supply A A is an adjustable extension on the feed supply A N A is a rocked Will cause the feedlgate A to rock back and forth and permit material to be fed from the hopper.

B is a pulsating frame open at top and bottom and partially closed at the bottom by supply discharging from the' lever which when oscillated or the screen B which screen is supported on the cross members B being provided at its forward lower end with a holding strip or selvage B adapted to be hooked over the pins'B 'in the frame.

B is :a flexible selvage of Wood or other suitable material rigidly attached at the upper rear end of the screen. B are hooks engaging this'selvage B B are screws projecting rearwardly from said hooks passing through the holding part B and adapted to bedrawn rearwardly by the nuts B to tighten the screen and hold it upon the cross members B which members it will be notedare so disposed that the screen is upwardly curved between its two ends and. the tension on the screen thus at all times. exercises a downward component tending to hold the screenfirmly on the supports B The flexibility of the selvage B and the separate hooks and screws permit of adjusting or controlling the tension in the screen at different points so 'asito' compensate for the differential Wear or differential stretch on the screen if this be needed. It will be noted that the screen frame is open at itslower forward end so that material which does not pass tlrough the screen may be fed over the end 0 it C, C are brackets rigidly attached to the frameor baseA.

C C are brackets rigidly attached to the pulsating frame B.

C C are flat supporting and throwing springs rigidly attached to the brackets C and C.

D is a housing mounted on a bracket D which bracket D together withthe bracket D are mounted base A.

on opposed .sides of the D is a rock. shaft'rotatably mounted in the bearings D, D on the brackets D D Df, D are rocker arngs keyed to theshaft 1) adjacent either side of the frame B and pivotally mounted omthe hangers D rigidly attached to the side of the frame B. Fingers D D projecting upwardly from the hangers D have pivotally mounted thereonthe-tie rods E slidable in the Washers E Springs E are interposed between the washers E and the washers E on these rods E to yieldingly support the forward end of the frame.

F is a cam or drive shaft rigidly mounted in the bearings F F on the frames D D F is a driving pulley rigidly attached to the shaft F and adapted to be driven by any suitable source of power not shown.

F is a four-point cam rigidly attached to the shaft F.

, F is a rocker arm rigidly attached to the rock shaft D having the contact block F in engagement with the cam F.

F is a filling opening whereby the housing D may be filled with grease.

F 8 is a discharge opening whereby it may be emptied or drained.

Referring to the cam I it will be noted that the angle a is substantially one-half of the angle 12 and that the cam rotates in the direction indicated by the arrow. It will be further noted that when the device is in the normal upright or raised positionas indicated in Fig. 2 the spring C is substantially parallel with the crank D.

G is an eccentric and has upon it the eccentric collar G Gr is a reach rod extending from the eccentric collar to the lever A and adjustable in position at its point of contact along sald lever.

It will be evident that, while I haveshown in my drawing an operative device, still many changes might be made in size, shape and arrangement of parts without departing materially from the spirit of my invention. I wish, therefore, that my drawing be regarded as in a sense diagrammatic.

The use and operation of my invention are as follows: With the parts in the assembled position as indicated in the drawing the housing or casing is first substantially filled with heavy oil or liquid grease. The machine is then started, the .cam rotating in the direction of the arrow. It will be noted that with the parts in the position shown in Fig. 3 as the cam rotates the block or pillow F will move rapidly inward toward the center of the cam shaft until the point m has been reached. It will then gradually be forced out until it reaches the point y. It will then rapidly return to the inside position until the point z is reached. This process will continue as long as the cam is rotated. It will be noted that the angular distance traversed between the points :0 y and z o is substantially twice as great as the angular distance ,traversed between the points K X and Y Z so that the upward movement caused by the spring will be twice as rapid as the downward movement against the spring caused by the rotation of the cam. The rotation of the cam will, of course, rock the rock shaft and cause the rocker arms to rotate depressing the screen but also pressing it backward so that the screen, when acted upon by the spring'will forward and upward and the ma- -'ter'i'al on the screen will also be shot forward and upward- This will result in projecting the material which is supported on time for the material to settle on the screen and be sifted through it instead of being batted up by the screen while still in the air and before being sifted, and as the screen pulsates the material will be thrown up diagonally and allowed to settle vertically under the influence of gravity, thus the material is being constantly agitated and tossed upward, the finer particles being sifted out. The weight of the screen and contents is of course all supported by the spring so that the sole function of the rocker arms and the cam shaft is to depress the whole mass against the tension of the springs and as this work is done slowly and evenly the load upon the bearings and upon the machinery is very slight, the violent jerking being done by the springs which are not likely to be harmed by it instead of being done by bearings which would be very materially harmed. d

The screen in use, of course, wears and be comes slack, and experience shows that this slackness is likely to be different at different parts of the screen and so this slackness may be compensated for by tightening up on the proper screws where needed and keeping it always tight over the cross pieces, thus keeping the screen upwardly bowed to prevent jerking or vibrating of the screen independent of the screen frame. 1

It will be noted that for every revolution v of the cam shaft the screen makes four strokes and it will further be noted that the eccentric feed drivingv device makes for every four strokes of the screen one stroke, and these strokes may be adjusted in length by adjusting the pivotal point of connection of the reach rod with the feed gate driving member. The feed thus may be controlled between any desired limits and the screen 'may be adjusted in any desired manner.

'supported therein and means for maintain-.

ing said fabric in a longitudinally upwardly curved position without transverse curva ture.

- 4. In a screen 'a frame, a screen fabric supported therein and means comprising supporting members on said frame and besaid fabric, said means comprising a flexible binding strip along one side of said screen and tension members applied to said binding strip, said tension means adapted to apply any desired tension independently to separate sections of the fabric.

6. In a pulsating screen a screen fabric and means for preventing transverse vibra-- tion thereof, said means comprising trans verse upwardly projecting supporting members intermediate its ends, said transverse members increasing in height toward the middle of the screen to give it an upwardly curved form, and means for holding said screen taut upon said members.

7. In a pulsating screen a screen fabric and means for preventing transverse vibration thereof, said means comprising transverse upwardly projecting supporting members intermediate its ends, said transverse members increasing in height toward the middle of the screen to give it an upwardly curved form, and means for holding said screen taut upon said members, said holding means comprising separate adjustable tension members along one side of said screen.

8. In.a pulsating screen a screen fabric, means for preventing transverse vibration thereof, said means comprising transverse upwardly projecting supporting members intermediate its ends; said transverse members increasing in height toward the middle of the screen to give it an upwardly curved form, and means for holding said screen taut uponsaid members, said holding means comprising separate adjustable tension members along one side of said screen, a flexible binding strip being interposed be-. tween said tension members and said screen to reinforce the edge of the screen.

\ 9. A pulsating screen, comprising a frame suspended at both ends so as to have simultaneous horizontal and vertical movement, in a direction inclined to the plane of the screening surface, in combination with con tinuously positively actuating means to impart such motion to the screen, the downward and backward movement taking twice as long as the upward and forward movement.

10. A pulsating screen, comprising a frame suspended at both ends so as to have simultaneous horizontal and vertical movement, in a direction inclined to the plane of the screening surface, in combination with continuously positively actuating means to impart such motion to the screen, the downward and backward movement taking twice as long as the upward and forward movement, said means containing a cam and arm in continuous operative engagement.

11. A pulsating screen, comprising a frame suspended at both ends so as to have simultaneous horizontal and.- vertical movement, in a direction inclined to the plane of ,the screening surface, in combination with continuously positively actuating means to impart such motion to the screen, the downward and backward movement taking twice as long as the upward and forward movement, said means containing a cam and arm in continuousoperative engagement, and a spring tending to raise the screen.

12. A pulsating screen, comprising a frame suspended at both ends by hangers so as to have simultaneous horizontal and vertical movement, in a direction inclined to the plane of the screening surface, in combination with a spring tending to raise the screen frame, an arm connected with the screen frame, and a cam in continuous operative engagement with such arm, with a spring and cam adapted to make the downward and backward movement of the screen take twice as long as the upward and forward move ment.

13. The combination with a screen fabric and frame upon which it is mounted and by which it is supported of means for anchoring firmly one side of the screen on the frame, a flexible strip rigidly attached all the way along the opposed side of the screen and a series of. removable clamping hooks engaging said flexible strip at points thereon, an adjustable connection between said hooks and the frame whereby the tension in different parts of the frame may by varying said adjustable connection be varied and controlled, said hooks being removably connected to the screen.

In testimony whereof, I aflix my signature in the presence of two witnesses this 4th day. of August 1913.

K EDGAR B. SYMONS.

Witnessesz' GENEVA Hm'rn, BEssrE S. RICE. 

